It is desirable to sterilize, pasteurize or otherwise heat treat heat-sensitive material by heating such heat-sensitive material, such as biological fluids, to high temperatures for very short time periods without affecting substantially the other desirable properties of the heat-sensitive material. U.S. Pat. No. 4,839,142, issued Jun. 13, 1989 and U.S. Pat. No. 4,975,246, issued Dec. 4, 1990, both disclose high temperature, short time heating systems and methods for the heating of heat-sensitive material to destroy substantially the pathogenic or other microorganisms, such as viruses, in the heat-sensitive material without substantially affecting other desirable properties of the heat-sensitive material, such as proteinaceous matter.
These patents disclose a system and method in which heat-sensitive material, such as a biological fluid, such as blood plasma or serum or tissue culture or tissue-type or other material, is rapidly heated by microwave energy to a selected temperature, held for a very short holding time and then rapidly cooled and then recovered. Typically, the method described provides for rapidly heating the heat-sensitive material at a rate of over 50.degree. C. per second, for example 50.degree. C. to 2000.degree. C. per second, for a heating time period typically less than one second to a preselected temperature of typically over about 60.degree. C. and to a temperature wherein the rate of reduction or destruction of the pathogenic organisms is greater than the rate of destruction of the heat-sensitive material by employing microwave energy to accomplish the rapid heating. The method includes holding the heated heat-sensitive material at a preselected temperature for a short holding time period which might be quite short, for example less than 0.05 seconds, and then rapidly cooling the heated heat-sensitive material to a preselected lower temperature, typically less than about 40.degree. C., or typically less than 30.degree. C., in a short time period to provide a cooled heat-sensitive material with the virus or agent destroyed or reduced. The heat-sensitive material is rapidly heated and rapidly cooled, while circulating the heat-sensitive material through a plastic tubing, with the total heating, holding and cooling time periods not greater than 1.0 seconds and sufficiently short so as not to substantially effect the desirable properties, such as the Factor VIII and IX properties of blood plasma or serum, but sufficient for the desirable reduction of the pathogenic organisms, viruses or microorganisms in the heat-sensitive material, typically to effect a multilog, e.g. six-log or more, cycle reduction of the microorganism.
It is desirable to provide for a new, efficient, controlled batch and continuous system and method for the high temperature, short time heating for heat-sensitive material which overcomes at least some of the disadvantages in the prior high temperature, short time heating system and method.